JP2692727B2 - Cylindrical connection type shock absorber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[Industrial field of application] It can be used as a measure to reduce the damage to both a ship and a fixed sea structure when a navigation ship collides with a fixed sea structure such as a pier of a long bridge. If an elastic body is used as the material of the cylindrical connection type buffer,
By utilizing the restoring force, it can also be used as a preventive measure against damage when the ship comes alongside. Further, it can be used not only for ships but also as a measure for reducing damage in the event of collision of any vehicle.

[0002]

2. Description of the Related Art A conventional buffer structure is a grid structure in which plates are arranged in a grid to form many compartments. Each element plate (called a girder plate) is provided with holes to reduce the weight. , The wave external force is being reduced. In addition, in order to avoid a sudden increase in the reaction force against the collision load, the girders are arranged in a staggered manner.

[0003]

In the conventional type of shock absorber, it is necessary to make more sections in the girder plate and to provide mitigation holes. Furthermore, in order to increase the uniformity of the reaction force, it is necessary to change the strength of the shock absorber from the outside that receives the collision, which requires man-hours and increases the manufacturing cost. Not only that, there is a sharp peak of the reaction force in the relationship between the reaction force and the amount of thrust into the bow (called reaction force curve), and this peak remains even if the girders are considered to be staggered. Forces cause damage to structures. Furthermore, the relationship between the absorbed energy and the amount of thrust into the bow (called the absorbed energy curve) varies greatly depending on the collision position, and the uniformity of the energy absorption rate is lacking. Therefore, the problem to be solved by the invention is to simplify the structure of the shock absorber so that there is no sharp peak of the reaction force in the reaction force curve and a flat portion of the reaction force appears, and the energy absorption rate is kept uniform. Therefore, the difference in the absorbed energy curve depending on the thrust position of the bow is to be reduced.

[0004]

A cylindrical connection type shock absorber has a shape as viewed from above as shown in FIG. 1, and has a simplified structure in which cylinders are connected and incorporated into an outer peripheral plate and an inner peripheral plate. Is. The inner peripheral plate is provided with a bolt hole for attaching the cylindrical connection type shock absorber, and the inner peripheral plate is fixed to the surface of the sea fixed structure. The length of the shock absorber depends on the protection range,
The depth can be set arbitrarily depending on the height to be protected.
The amount of overhang of the shock absorber is related to the amount of absorbed energy.

When the bow of the collision ship enters the cylindrical connection type shock absorber, the collision energy is absorbed by the deformation of the outer peripheral plate and the deformation of the cylinder. At this time, the sharp peak of the reaction force is alleviated by the deformation utilizing the flexibility in the lateral direction with respect to the axis of the cylinder, and at the same time, the energy distribution due to the deformation is changed by changing the thicknesses of the outer peripheral plate and the cylinder, and the energy due to the bow thrust position is changed. The difference in absorption rate is reduced.

[0006]

First, the amount of energy to be absorbed by the collision scale of the ship, that is, the shock absorber, and the allowable load so that the structure is not destroyed are set. Next, it is considered that the absorbed energy is proportional to the cube of the scale ratio and the load is proportional to the square of the scale ratio. At this time, in the reaction force curve, if the reaction force close to the flat portion is the allowable load, the absorbed energy efficiency is good.

The absorbed energy can be obtained by integrating the reaction force curve with respect to the amount of thrust into the bow up to the amount of overhang of the shock absorber. A model in which the amount of overhang is determined so that the value of this absorbed energy exceeds the collision energy of the ship is converted into the actual size, and the size of the actual shock absorber is determined.

[0008]

EXAMPLES FIGS. 2 and 3 show a scale model for a crushing experiment. FIG. 2 shows the case of the bow thrust condition (A) when the bow load acts on the cylindrical portion, and FIG. 3 shows the case of the bow thrust condition (B) when the bow load acts on the middle of the cylinder. The characteristics of the shock absorber can be understood by comparing the crushing experiments under these two extreme conditions for entering the bow. FIG. 4 shows a reaction force curve corresponding to each of the bow thrust conditions, and FIG. 5 shows an absorbed energy curve obtained by integrating the reaction force curve with respect to the bow thrust amount. As shown in FIG. 4, no sharp peak of the reaction force is seen in the reaction force curve, and a fairly wide flat portion is obtained. In the absorbed energy curve in Fig. 5, there is almost no difference due to the conditions of the thrusting into the bow, and the uniformity of the energy absorption rate is maintained.

[0009]

According to the present invention, it is possible to effectively reduce the damage to both a ship and a sea fixed structure when the sailing ship collides with the sea fixed structure. Therefore, safety measures for marine traffic are improved. To do.

[Brief description of the drawings]

FIG. 1 is a view of a cylindrical connection type shock absorber as viewed from above.

FIG. 2 is a scaled model of a cylindrical connection type shock absorber for a crushing experiment,
It is a figure of a model corresponding to a bow thrust condition (A).

[Fig. 3] A scale model of a cylindrical connection type shock absorber for a crushing experiment,
It is a figure of a model corresponding to a bow thrust condition (B).

[Fig. 4] Fig. 4 shows experimental results of reaction force curve. The reaction force curve of the cylindrical connection type buffer does not have a sharp peak of reaction force, and the reaction force becomes a flat surface that is almost horizontal with respect to the thrust amount of the bow. It is the figure which showed that the part which has appeared.

FIG. 5 is an absorbed energy curve obtained by integrating the reaction force curve of FIG. 4 with respect to the amount of thrust into the bow, showing that there is almost no difference in the absorbed energy curves between the thrust conditions (A) and (B) of the bow. It is a figure showing that the uniformity of is maintained.

[Explanation of symbols]

 1 collision bow, 2 diameter of cylinder, 3 outer peripheral plate, 4 inner peripheral plate, 5 range of 1 connecting cylinder, 6 central angle showing protection range of shock absorber, 7 overhang amount of shock absorber, 8 depth of shock absorber , 9 Shock absorber mounting holes provided on the inner peripheral plate

Claims (1)

(57) [Claims] 1. A type of structure (referred to as a shock absorber) attached to a sea fixed structure such as a pier of a long bridge in order to effectively absorb kinetic energy at the time of collision of a ship and reduce damage caused by the collision. in, connecting the cylinder made of steel, cylindrical coupling type buffer Engineering incorporating it out <br/> peripheral plate and the inner peripheral plates made of steel.